Ramstein is so big, that there just has to be a model flying group on base, and even though they are probably all flying glow or gas models, I have yet to find a model flyer who is not interested in trying something new - especially when someone else is paying

I suggest your son contacts whoever it is on base that has a list of all the recreation activities, or contacts a local model flying group through the local model shop - though there could be language difficulties.